| Oxymatrine is a kind of quinolizidine Alkaloid that extracted from the traditional Chinese medicine kuhseng, Euchresta japonica and foxtail-like sophora herb and seed. As it was distributed all over the body and has short elimination half time, this topic focus on the preparation method and quality control of OM ordinary liposomes as well as PEGs liposomes. The research has completed the study on preparation technology, quality control and pharmacokinetics in rats, and it reached the goals that prolong the action time and incrase the stability in vivo.The preformulation study has obtained important parameters that can instruct the preparation of OM liposomes, including the determination of the apparent distribution coefficient of n-octyl alcohol to water and the study on hydration conditions. The research indicated that the distribution coefficient of OM increased with pH raise in water. The apparent distribution coefficient of n-octyl alcohol to water will be in constancy when pH raise in water.was exceeding 7.4. The logP value was-0.66 as the P value was 0.22, and it can be concluded that OM was a water-solubility medicine as logP value was below-0.3. The topic optimized hydration conditions during the preparation process, and discussed the parameters for each preparation method, including hydration time for liposome film; amount of water in aqueous phase; agitation conditions; speed; temperature and so on. It can be concluded that organic solvent was chloroform 10ml; 100ml pear shape bottle as the reaction container; the best experimental condition are 100 r-min-1,0.06MPa for microfilm method. Aether was organic phase; and retaining the ratio of aqueous phase to ether phase was 1:3 (V/V). The best expertional condition were as follws:bath temperature set at 28℃, the degree of vacuum was at 0.04MPa, and with a rotation speed at 80r·min-1.HPLC analytical method of OM was established for determining of OM as well as the entrapment efficiency of liposomes. Free drug was separated from OM liposomes by dialysis method, sephadex column chromatography and microcolumn centrifugalization. Microcolumn centrifugalization was the best way to determine entrapment efficiency.Preparation methods of OM ordinary liposomes and PEGs liposomes were highlight in this study. Ordinary liposomes were prepared by two kinds of film material (PCI, PCII). The preparation method and prescription composition were determined using different film material. The entrapment efficiency of OM liposomes prepared with PCI(soybean lecithin, the content of phosphatidyl choline>60%) was 56.30% with a pH gradient method(blank liposomes were prepared by thin-film dispersion). The entrapment efficiency of OM liposomes prepared with PCII(soybean lecithin, the content of phosphatidyl choline> 95%) was 71.70% with a ammonium sulfate gradient method(blank liposomes were prepared by thin-film dispersion). The different influencing factors in preparation technology of liposomes were also studied by orthogonal experiment design, and the best technical parameters and prescriptions were also determined. The best prescription was PCII 60mg, cholesterol 15mg, vitamin E 0.1 mg, blank liposomes were prepared by thin-film dispersion, ammonium sulfate gradient were formed by dialysis, incubation temperature was 55℃for 1 hour. To prepare the OM PEGs liposomes after the ordinary liposomes. The best prescription was hydriding soybean lecithin 50mg, cholesterol 30mg, PEG2000-DSPE 10mg, OM 10mg, blank liposomes were prepared by thin-film dispersion, ammonium sulfate gradient were formed by dialysis, incubation temperature was 60℃for 1.5 hour. The average entrapment efficiency was 57.24%. In order to improve the storage stability of liposomes, the study on the lyophilization of OM ordinary liposomes was done. The optimization and confirmation of lyophilization was also completed.The quality evaluation of OM liposomes, including observation of morphous, grain size and distribution, assaying of OM, determination of releasing in vitro, determination of entrapment efficiency and leakage ratio.Pharmacokinetic characteristics of OM liposomes of rats in vivo were studied. In this experiment, the determination of OM concentration in rats'plasma by HPLC was completed for the sophoridine as the internal standard. The t1/2 (β) of OM PEGs-liposomes was increased by 5.66 times compared with OM solution group, and 2.33 times compared with ordinary liposomes in the same dosage. It is demonstrated that OM eliminates faster than OM PEGs liposomes in vivo, and OM PEGs liposomes can maintain more time and AUC0-t of it was increased by 6.49 times compared with OM solution group. At the same time, the AUC0-t of OM ordinary liposomes was 3.6 times greater than that of the OM solution group. It can be seen that lipsomes can improve the bioavailability of OM in rats in vivo.The topic brings new ideas in this aera represented as follows:①The study focused on the preparation of OM liposomes, and investigated the preparation methods of liposomes using the PC with low content. The prepatation cost can be cut down in a certain extent and increased the utilization rate of PC.②OM PEGs-liposomes were prepared by ammonium sulfate gradient method, and investigated the pharmacokinetic characteristics. It was demonstrated the prapared PEGs-liposomes can prolong the resistance time, and reduce elimination in rats.③Investigated the preparation technology of OM liposomes by using ammonium sulfate gradient and microcolumn centrifugalization, and increased the entrapment efficiency of OM liposomes in a certain extent. The topic has far-reaching significance to the selective enrichment of OM in the lesion site and its slow-release effect, and ultimately it increase the pharmacological effects and improve its biological stability, and reach the purpose of reducing adverse drug reactions. |
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